A United Methodist Church appeals panel has voted to restore a pastor who was defrocked last year for presiding over his gay son's wedding.

Reverend Frank Schaefer was granted his pastoral credentials following Tuesday's decision, clearing the way for his return to the pulpit.

The nine-person panel ruled the jury that convicted Rev Schaefer erred when fashioning his punishment.

Rev Schaefer, who preaches in central Pennsylvania, was handed a 30-day suspension last year after officials learned that he had presided over his son's gay wedding in Massachusetts in 2007.

Church officials then voted to defrock him in December after he refused to promise that he would not officiate same-sex marriage ceremonies in the future.

Although the Methodist church accepts gay and lesbian members, it rejects the practise of homosexuality as "incompatible with Christian teaching".

Rev Schaefer appealed the decision on the grounds that he could not be punished based on an assumption that he would break church law in the future.

The appeals panel agreed, concluding that revoking his credentials "cannot be squared with the well-established principle that our clergy can only be punished for what they have been convicted of doing in the past, not for what they may or may not do in the future".

The panel upheld Rev Schaefer's previously served suspension, and said he should receive back pay dating to when the suspension ended in December.

The Methodist Church has the option of appealing the ruling to its highest court, the Judicial Council.